The catastrophe, "Hammer of Eden," caused the death of six billion people and submerged 90% of the land. Fourteen years later, the New United Nations were established to seek peace on the devastated earth. Keel is a boy residing in the town of Yabitsu, a region that thrived thanks to the energy supplied by the nuclear generator left behind by the disaster. His next of kin, Aoi, serves as the secretary general of the New United Nations. She regards the catastrophe as a chance to build a new world where nations can assist each other in bridging racial and religious divides. However, her attempts to achieve this vision are thwarted by the nations' refusal to change. Gould, a military officer, believes that order can only be imposed through military force. Utilizing Ulysses, a nuclear submarine, and his crew, which includes Keel's brother Tean, Gould executes a coup by declaring war on the New United Nations during his assault on Yabitsu.